Modern low-intensity conflicts are won and lost on their ragged edges. Nations act as though the careful plans of their militaries and intelligence operations can harness the chaos of combat and guide it to advance their interests. And then the unplanned happens, collateral damage occurs, and it has a bigger impact on politics and the position of combatants than all the calculated elements of the conflict added up.

While the Israeli government can and repeatedly does justify its actions against Hamas as self-defense, it cannot argue away the deaths of four children on the beach or, for that matter, the large number of other civilian victims of its attacks.The government may take every precaution, use the most advanced smart munitions available, and periodically stop its warring to offer humanitarian relief. But when innocent children die while playing on the beach, every justification rings hollow, every precaution is revealed to be callously inadequate. When a child’s lifeless body lies in a Ukrainian field to which it has fallen from the sky, the prevarications and plausible deniability that may have been useful in managing less horrifying incidents lose their effectiveness.

From a purely political perspective, such tragedies, isolated though they may be, instantly dominate the narrative of a conflict because they speak to the heart of observers — whereas government speeches, Twitter feeds, and press releases seem too coldly rational and calculated, too soulless and self-interested. There are no arguments a political leader or a press officer can make that trump horror or anguish. There is no moral equation that offers a satisfactory calculus to enable us to accept the death of innocents as warranted.

In a moment, the rationales for waging such "limited actions" become moot. Arguments about self-defense ring hollow when the defenseless are murdered. Indeed, the notion that such actions could be "limited," which is to say managed or contained, is belied by the unintended consequences like those that have dominated the news this week. This is doubly tragic in the case of this most recent round of fighting between the Israelis and their Palestinian neighbors — which now sees Israel Defense Forces troops on the ground in Gaza — because of the inherent futility of the efforts of both sides. We have seen these skirmishes before.

Never once have they improved the situation of either side. Neither can damage the other sufficiently to change the balance of power between them. No action that either can muster can be punitive enough to change the behavior of the other.

Nonetheless, both parties to the conflict in Israel and Gaza seem to still be under the delusion that these regularly repeated outbursts actually serve a purpose. Leaders on both sides have lost all sense that when you share a land, you share each other’s children, and that they belong not to the flawed nations of today but to the promise of what might come tomorrow. The sight of dead children not only weakens Israel politically and dents the country’s international standing, but it taints every defensible action Israel might take and devalues any future peace by literally having snuffed it out for those who might have benefited from that better future.

The sad part is that we all knew such a consequence would come. Yes, violent extremists who pose a threat to Israel have been killed in this latest round of hostilities, but history has shown they are like dragon’s teeth: remove one, another grows in its place. But when bystanders are killed in action, not only does that speed the process by which new extremists are created, but it strengthens Hamas’s case that Israel is the callous user of disproportionate force, the problem the world must help it solve. There is no question that Israel is weaker today as a result of the death of those four boys than it was a few days ago when they were still able to play soccer on that beach.

Similarly, just a few days ago, Russian President Vladimir Putin stood among his fellow leaders of the BRICS nations and basked in their support. They would stand by him against American and European sanctions. But if it is proved that Russian-supported separatists using Russian weapons were, as it seems, responsible for the downing of Malaysia Airlines Flight 17 and the deaths of 298 passengers and crew members, then it will be much harder for the friends of the Russian leader to embrace him or his brazen efforts to destabilize Ukraine.*

For all his mastery in seizing Crimea without firing a shot, for slipping Spetsnaz special forces and intelligence units into Ukraine in such a way that not even his enemies dared call it an invasion, for leveraging the unrest to influence his neighbor, it could well be that this tragedy will ultimately define this conflict in the eyes of the world. Certainly, it will rewrite its narrative.

Putin has already said that it’s Ukraine’s fault. In time, he may come to blame it on rogue separatists. But even if a trigger-happy Cossack irregular is to blame, the slaughter of innocents still will likely redound to the disadvantage of the apparent sponsor.

In total warfare, it is easier to shrug off collateral damage as the cost of achieving a vital goal, of survival. But in more limited conflicts, it can reset the political context that is as much a part of the overall battle as is the use of force. Random errors can as a consequence become great defeats. When innocents die, standard military metrics for success or failure pale in comparison with the human costs depicted so graphically in the media — highlighting once again with indelible and deeply disturbing images the hubris of leaders who delude themselves into believing they can control the uncontrollable.

Update, July 18, 2014: This article has been updated to state that 298 passengers and crew members died in the downing of Malaysia Airlines Flight 17. An earlier version stated that 295 died, a death toll that had been earlier reported. (Return to reading.)